2002 JEEP LIBERTY fused ignition switch

lating (AM) and Frequency Modulating (FM) com-
mercial frequency ranges.
The audio system components operate on battery
current received through a fuse in the Junction Block
(JB) on a fused ignition switch output (run-acc) cir-
cuit so that the system will only operate when the
ignition switch is in the Run or Accessory positions.
On vehicles that are equipped with the optional
remote radio switches, the Body Control Module
(BCM) receives hard wired resistor multiplexed
inputs from the remote radio switches. The program-
ming in the BCM allows it to process those inputs
and send the proper messages to the radio receiver
over the Programmable Communication Interface
(PCI) bus network to control the radio volume up or
down, station seek up or down, preset station
advance, and mode advance functions.
Refer to the owner's manual for more information
on the features, use and operation of each of the
available audio systems.
DIAGNOSIS AND TESTING - AUDIO
Any diagnosis of the Audio system should
begin with the use of the DRB diagnostic tool.For information on the use of the DRB, refer to
the appropriate Diagnostic Service Manual.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
AUDIO SYSTEM DIAGNOSIS TABLE
CONDITION POSSIBLE CAUSES CORRECTION
NO AUDIO 1. Fuse faulty. 1. Check radio fuse and Ignition-Off Draw (IOD)
fuse in Junction Block (JB). Replace fuses, if
required.
2. Radio connector faulty. 2. Check for loose or corroded radio connector.
Repair, if required.
3. Wiring faulty. 3. Check for shorted or open wires. Repair wiring,
if required.
4. Radio ground faulty. 4. Check for continuity between radio chassis and
a known good ground. There should be
continuity. Repair ground, if required.
5. Radio faulty. 5. Refer to appropriate Diagnostic Service
Manual.
6. Speakers faulty. 6. Replace speaker as necessary.
NO RADIO DISPLAY 1. Fuse faulty. 1. Check radio fuse and Ignition-Off Draw (IOD)
fuse in Junction Block (JB). Replace fuses, if
required.
2. Radio connector faulty. 2. Check for loose or corroded radio connector.
Repair, if required.
3. Wiring faulty. 3. Check for battery voltage at radio connector.
Repair wiring, if required.
4. Radio ground faulty. 4. Check for continuity between radio chassis and
a known good ground. There should be
continuity. Repair ground, if required.
8A - 2 AUDIOKJ
AUDIO (Continued)

DIAGNOSIS AND TESTING - AMPLIFIER
CHOKE AND RELAY
Any diagnosis of the Audio system should
begin with the use of the DRB diagnostic tool.
For information on the use of the DRB, refer to
the appropriate Diagnostic Service Manual.
The amplifier choke and relay is used to switch
power to the individual speaker amplifiers used with
the premium speaker package. The amplifier choke
and relay is serviced only as a unit. If all of the
speakers are inoperative the amplifier choke and
relay should be inspected. Before replacement, make
the following inspections of the amplifier choke and
relay circuits. For complete circuit diagrams, refer to
the appropriate wiring information. The wiring infor-
mation includes wiring diagrams, proper wire and
connector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
(1)
Check the fused B(+) fuse in the junction block. If
OK, go to Step 2. If not OK, replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the junction block. If OK, go to Step 3. If not OK,
repair the open fused B(+) circuit to the battery as
required.
(3) Disconnect the instrument panel wire harness
connector from the amplifier choke and relay. Check
for battery voltage at the fused B(+) circuit cavity of
the instrument panel wire harness connector for the
amplifier choke and relay. If OK, go to Step 4. If not
OK, repair the open fused B(+) circuit to the junction
block fuse as required.
(4) Probe the ground circuit cavity of the instru-
ment panel wire harness connector for the amplifier
choke and relay. Check for continuity to a good
ground. There should be continuity. If OK, go to Step
5. If not OK, repair the open ground circuit to ground
as required.
(5) Turn the ignition switch to the RUN position
and turn the radio ON. Check for battery voltage at
the radio 12-volt output circuit cavity of the instru-
ment panel wire harness connector for the amplifier
choke and relay. If OK, go to Step 6. If not OK,
repair the open radio 12-volt output circuit to the
radio as required.
(6) Turn the radio and ignition switches to the
OFF position. Reconnect the instrument panel wire
harness connector to the amplifier choke and relay.
Check for battery voltage at the amplified speaker
(+) circuit cavity of the instrument panel wire har-
ness connector for the amplifier choke and relay.
There should be zero volts. Turn the ignition and
radio switches to the ON position. There should now
be battery voltage. If OK, repair the open amplified
speaker (+) circuits to the speaker-mounted amplifi-ers as required. If not OK, replace the faulty ampli-
fier choke and relay.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove knee blocker cover and knee blocker.
(3) Disconnect the electrical harness connector
from the amplifier choke and relay (Fig. 1).
(4) Remove mounting screws and amplifier choke
and relay.
INSTALLATION
(1) Install the amplifier choke and relay.
(2) Install the mounting screws.
(3) Connect the electrical harness connector.
(4) Install knee blocker cover and knee blocker.
(5) Connect the battery negative cable.
ANTENNA BODY & CABLE
DESCRIPTION
The antenna body and cable is secured below the
fender panel by the antenna cap nut through a
mounting hole in the side of the right front fender.
The primary coaxial antenna cable is then routed
beneath the fender sheet metal and through a entry
hole in the right cowl side panel into the interior of
the vehicle. Inside the vehicle, the primary coaxial
cable is connected to a secondary instrument panel
antenna coaxial cable with an in-line connector that
is located behind the right kick panel. The secondary
coaxial cable is then routed behind the instrument
panel to the back of the radio.
Fig. 1 RADIO CHOKE
1 - RADIO CHOKE
2 - MOUNTING SCREWS
8A - 4 AUDIOKJ
AMPLIFIER CHOKE AND RELAY (Continued)

(2) Remove the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - REMOVAL).
(3) Disconnect the antenna cable from radio by
pulling the locking antenna connector away from
radio (Fig. 5).
(4) Disengage each of the retainers that secure the
cable to the instrument panel (Fig. 6).
(5) Remove the cable from the instrument panel.
INSTALLATION
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Position the instrument panel antenna cable
onto the instrument panel.
(2) Engage each of the retainers that secure the
cable to the back side of the instrument panel.
(3) Connect cable to radio.
(4) Install instrument panel (Refer to 23 - BODY/
INSTRUMENT PANEL/INSTRUMENT PANEL
ASSEMBLY - INSTALLATION).
(5) Connect the battery negative cable.
RADIO
DESCRIPTION
Available factory-installed radio receivers for this
model include an AM/FM/cassette with CD changer
control feature (RBB sales code), an AM/FM/cassette/
CD/graphic equalizer with CD changer control fea-
ture (RBP sales code), or an AM/FM/CD/ with CD
changer control feature (RBK sales code). All factory-
installed radio receivers can communicate on the
Programmable Communications Interface (PCI) data
bus network. All factory-installed receivers are stereo
Electronically Tuned Radios (ETR) and include an
electronic digital clock function.
These radio receivers can only be serviced by an
authorized radio repair station. See the latest War-
ranty Policies and Procedures manual for a current
listing of authorized radio repair stations.
OPERATION
The radio receiver operates on ignition switched
battery current that is available only when the igni-
tion switch is in the On or Accessory positions. The
electronic digital clock function of the radio operates
on fused battery current supplied through the IOD
fuse, regardless of the ignition switch position.
For more information on the features, setting pro-
cedures, and control functions for each of the avail-
able factory-installed radio receivers, refer to the
owner's manual. For complete circuit diagrams, refer
to the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, details of wire har-
Fig. 5 ANTENNA TO RADIO
1 - RADIO
2 - LOCKING ANTENNA CONNECTOR
3 - INSTRUMENT PANEL ANTENNA CABLE
Fig. 6 INSTRUMENT PANEL ANTENNA CABLE
1 - INSTRUMENT PANEL ANTENNA CABLE
2 - ANTENNA BODY AND CABLE
8A - 8 AUDIOKJ
INSTRUMENT PANEL ANTENNA CABLE (Continued)

A chime warning system is standard factory-in-
stalled equipment on this model. The chime warning
system uses a single chime tone generator that is sol-
dered onto the electronic circuit board that is integral
to the ElectroMechanical Instrument Cluster (EMIC)
to provide an audible indication of various vehicle
conditions that may require the attention of the vehi-
cle operator or occupants (Fig. 1). The microproces-
sor-based EMIC utilizes electronic chime request
messages received from other electronic modules in
the vehicle over the Programmable Communications
Interface (PCI) data bus network along with hard
wired inputs to the cluster microprocessor to monitor
many sensors and switches throughout the vehicle.
In response to those inputs, the integrated circuitry
and internal programming of the EMIC allow it to
control audible outputs that are produced through its
on-board chime tone generator.
The EMIC circuitry and its chime tone generator
are capable of producing each of the four following
audible outputs:
²Fixed Duration Beep- A short, sharp, single
tactile ªbeep-likeº tone that is about 150 milliseconds
in duration.
²Single Chime Tone- A single ªbong-likeº chime
tone.
²Slow Rate Repetitive Chime- Repeated
chime tones that are issued at a slow rate of about
50 ªbong-likeº tones per minute.
²Fast Rate Repetitive Chime- Repeated chime
tones that are issued at a fast rate of about 180
ªbong-likeº tones per minute.
Hard wired circuitry connects the EMIC and the
various chime warning system switch and sensor
inputs to their electronic modules and to each other
through the electrical system of the vehicle. These
hard wired circuits are integral to numerous wire
harnesses, which are routed throughout the vehicle
and retained by many different methods. These cir-
cuits may be connected to each other, to the vehicle
electrical system and to the chime warning system
through the use of a combination of soldered splices,
splice block connectors, and many different types of
wire harness terminal connectors and insulators.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices and grounds.
The EMIC chime warning system circuitry and
integral chime tone generator cannot be adjusted or
repaired. If the EMIC or the chime tone generator
are damaged or faulty, the EMIC unit must be
replaced.OPERATION
The chime warning system is designed to provide
an audible output as an indication of various condi-
tions that may require the attention or awareness of
the vehicle operator or occupants. The chime warning
system components operate on battery current
received through a fused B(+) fuse in the Junction
Block (JB) on a non-switched fused B(+) circuit so
that the system may operate regardless of the igni-
tion switch position. However, the chime warning
system also monitors the ignition switch position so
that some chime features will only occur with igni-
tion switch in the On position, while others occur
regardless of the ignition switch position.
The chime warning system provides an audible
indication to the vehicle operator or occupants under
the following conditions:
²Airbag Indicator Warning- The ElectroMe-
chanical Instrument Cluster (EMIC) chime tone gen-
erator will generate one, short, ªbong-likeº chime
tone when the ignition switch is in the On position,
and an electronic message is received over the Pro-
grammable Communications Interface (PCI) data bus
from the Airbag Control Module (ACM) requesting
ªAirbagº indicator illumination. This warning will
only occur following completion of the ªAirbagº indi-
cator bulb test, and will only occur once during an
ignition cycle. The ACM uses internal programming,
hard wired inputs from the front Supplemental
Restraint System (SRS) components and, on vehicles
so equipped, electronic messages received over the
PCI data bus from each Side Impact Airbag Control
Module (SIACM) to determine the proper ªAirbagº
indicator messages to send to the EMIC.
²Anti-Lock Brake Indicator Warning- The
EMIC chime tone generator will generate one, short,
ªbong-likeº chime tone when the ignition switch is in
the On position, and an electronic message is
received over the PCI data bus from the Controller
Anti-lock Brake (CAB) requesting ªAntilock Brake
System (ABS)º indicator illumination. This warning
will only occur following completion of the ªABSº
indicator bulb test, and will only occur once during
an ignition cycle. The CAB uses internal program-
ming, hard wired inputs from the Antilock Brake
System (ABS) components, and electronic messages
received over the PCI data bus from the Powertrain
Control Module (PCM) to determine the proper
ªABSº indicator messages to send to the EMIC.
²Compass Mini-Trip Computer Reset- The
EMIC chime tone generator will generate one, short,
fixed duration ªbeep-likeº chime tone when the igni-
tion switch is in the On position, and an electronic
message is received over the PCI data bus from the
optional Compass Mini-Trip Computer (CMTC)
requesting that the CMTC elapsed time, average fuel
8B - 2 CHIME/BUZZERKJ
CHIME WARNING SYSTEM (Continued)

flip-up glass ajar switch, the hood ajar switch (in
required markets only), and the Remote Keyless
Entry (RKE) module to control the features of the
optional Vehicle Theft Security System (VTSS).
Hard wired circuitry connects the BCM to the elec-
trical system of the vehicle. These hard wired circuits
are integral to several wire harnesses, which are
routed throughout the vehicle and retained by many
different methods. These circuits may be connected to
each other, to the vehicle electrical system and to the
BCM through the use of a combination of soldered
splices, splice block connectors, and many different
types of wire harness terminal connectors and insu-
lators. Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, further
details on wire harness routing and retention, as well
as pin-out and location views for the various wire
harness connectors, splices and grounds.
Many of the electronic features in the vehicle con-
trolled or supported by the BCM are programmable
using a customer programming procedure or the
DRBIIItscan tool. In addition, the BCM software is
Flash compatible, which means it can be repro-
grammed using Flash reprogramming procedures.
However, if any of the BCM hardware components is
damaged or faulty, the entire BCM unit must be
replaced.
OPERATION
The microprocessor-based Body Control Module
(BCM) monitors many hard wired switch and sensor
inputs as well as those resources it shares with other
electronic modules in the vehicle through its commu-
nication over the Programmable Communications
Interface (PCI) data bus network. The internal pro-
gramming and all of these inputs allow the BCM
microprocessor to determine the tasks it needs to
perform and their priorities, as well as both the stan-
dard and optional features that it should provide.
The BCM programming then performs those tasks
and provides those features through both PCI data
bus communication with other electronic modules
and through hard wired outputs through a number of
driver circuits, relays, and actuators. These outputs
allow the BCM the ability to control numerous acces-
sory systems in the vehicle.
The BCM operates on battery current received
through a fuse in the Junction Block (JB) on a non-
switched fused B(+) circuit, through another fuse in
the JB on a fused ignition switch output (run-start)
circuit, and through a third fuse in the JB on a fused
ignition switch output (run-acc) circuit. This arrange-
ment allows the BCM to provide some features
regardless of the ignition switch position, while other
features will operate only with the ignition switch inthe On, Start, and/or Accessory positions. All of the
battery current circuits are connected to the BCM
through the JB/BCM connector. The BCM receives
ground through five separate circuits. Three of these
circuits are connected to the BCM through a connec-
tor and take out of the instrument panel wire har-
ness on three separate ground circuits, while the
other two circuits are connected to the BCM through
the JB/BCM connector. All of these circuits are
grounded through a splice block located in the instru-
ment panel wire harness with an eyelet terminal con-
nector that is secured by a nut to a ground stud on
the driver side instrument panel end bracket near
the JB.
The BCM monitors its own internal circuitry as
well as many of its input and output circuits, and
will store a Diagnostic Trouble Code (DTC) in elec-
tronic memory for any failure it detects. These DTCs
can be retrieved and diagnosed using a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
HARD WIRED INPUTS The hard wired inputs to
the BCM include the following:
²A/C on/off control
²Ambient temperature sensor signal
²Body control module flash enable
²Door lock switch mux
²Driver door ajar switch sense
²Flip-up glass ajar switch sense
²Flip-up glass release switch sense
²Fog lamp switch sense
²Front wiper park switch sense
²Front wiper switch mux
²Front washer pump driver
²Fused B(+)
²Fused ignition switch output (run-acc)
²Fused ignition switch output (run-start)
²Headlamp switch mux
²High beam switch sense
²Hood ajar switch sense - premium with
VTSS - in markets where required only
²Key-in ignition switch sense
²Left cylinder lock switch sense - premium
with VTSS only - omitted in some markets as
required
²Panel lamps dimmer switch mux
²Passenger doors ajar switch sense (input
from three ajar switches connected in parallel)
²Radio control mux - premium with remote
radio switches only
²Rear courtesy lamp control
²Rear window defogger control
²Rear wiper intermittent driver
²Rear wiper on driver
²Right cylinder lock switch sense - premium
with VTSS only - omitted in some markets as
required
KJELECTRONIC CONTROL MODULES 8E - 5
BODY CONTROL MODULE (Continued)

OPERATION
The ISO relay consists of an electromagnetic coil, a
resistor or diode, and three (two fixed and one mov-
able) electrical contacts. The movable (common feed)
relay contact is held against one of the fixed contacts
(normally closed) by spring pressure. When electro-
magnetic coil is energized, it draws the movable con-
tact away from normally closed fixed contact, and
holds it against the other (normally open) fixed con-
tact.
When electromagnetic coil is de-energized, spring
pressure returns movable contact to normally closed
position. The resistor or diode is connected in parallel
with electromagnetic coil within relay, and helps to
dissipate voltage spikes produced when coil is de-en-
ergized.
DIAGNOSIS AND TESTING - STARTER RELAY
The starter relay is located in the Power Distribu-
tion Center (PDC) in engine compartment. Refer to
label on PDC cover for relay location.
RELAY TEST
(1) Remove starter relay (Fig. 13) from PDC.
(2) A relay in de-energized position should have
continuity between terminals 87A and 30, and no
continuity between terminals 87 and 30. If OK, go to
Step 3. If not OK, replace faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   5 ohms. If OK, go to Step
4. If not OK, replace faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, perform following Relay Circuit Test.
If not OK, replace faulty relay.
RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) is
connected to battery voltage and should be hot at all
times. If OK, go to Step 2. If not OK, repair open cir-
cuit to fused B(+) fuse in PDC as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to common feed terminal (30) in energized
position. This terminal supplies battery voltage to
starter solenoid field coil. There should be continuity
between cavity for relay terminal 87 and starter sole-
noid terminal at all times. If OK, go to Step 4. If not
OK, repair open engine starter motor relay output
circuit to starter solenoid as required.
(4) The coil battery terminal (86) is connected to
electromagnet in relay. It is energized when ignition
switch is held in Start position. On vehicles with amanual transmission, the clutch pedal must be
blocked in fully depressed position for this test.
Check for battery voltage at cavity for relay terminal
86 with ignition switch in Start position, and no volt-
age when ignition switch is released to On position.
If OK, go to Step 5. If not OK with a manual trans-
mission, disconnect clutch pedal position switch wire
harness connector and install a jumper wire between
two cavities in body half of connector and check for
battery voltage again at cavity for relay terminal 86.
If now OK, replace faulty clutch pedal position
switch. If still not OK with a manual transmission or
if not OK with an automatic transmission, check for
open or shorted fused ignition switch output (start)
circuit to ignition switch and repair as required. If
fused ignition switch output (start) circuit is OK,
refer toIgnition Switch and Key Lock Cylinder.
(5) The coil ground terminal (85) is connected to
electromagnet in relay. On vehicles with manual
transmission, it is grounded at all times. On vehicles
with automatic transmission, it is grounded through
park/neutral position switch only when gearshift
selector lever is in Park or Neutral positions. Check
for continuity to ground at cavity for relay terminal
85. If not OK with a manual transmission, repair
open park/neutral position switch sense circuit to
ground as required. If not OK with an automatic
transmission, check for open or shorted park/neutral
position switch sense circuit to park/neutral position
switch and repair, as required. If park/neutral posi-
tion switch sense circuit checks OK, refer toPark/
Neutral Position Switch.
Fig. 13 STARTER RELAY (ISO MICRO RELAY)
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
8F - 42 STARTING SYSTEMKJ
STARTER MOTOR RELAY (Continued)

no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 60.7 to 80.3 ohms. If OK, go to
Step 3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, see the Relay Circuit Test in this
group. If not OK, replace the faulty relay.
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) is
connected to battery voltage and should be hot at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the PDC fuse as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the rear glass and outside rear view mirror heat-
ing grids and the defogger switch indicator lamp.
There should be continuity between the cavity for
relay terminal 87 and the rear window defogger relay
output circuit cavities of the rear glass heating grid
connector, both outside rear view mirror heating grid
connectors, and the defogger switch connector at all
times. If OK, go to Step 4. If not OK, repair the open
circuit(s) as required.(4) The coil ground terminal (85) is connected to
the electromagnet in the relay. This terminal is pro-
vided with ground by the instrument cluster rear
window defogger timer and logic circuitry to energize
the defogger relay. There should be continuity to
ground at the cavity for relay terminal 85 when the
defogger switch is turned On. However, with the
defogger relay removed, the defogger switch indicator
lamp will not light to show that the defogger system
is turned On. Be certain that you depress the defog-
ger switch at least twice to confirm that the system
is turned on during this test. If OK, go to Step 5. If
not OK, repair the open circuit to the HVAC control
head as required.
(5) The coil battery terminal (86) is connected to
the electromagnet in the relay. It is connected to
fused ignition switch output voltage and should be
hot when the ignition switch is in the run position.
Check for battery voltage at the cavity for relay ter-
minal 86 with the ignition switch in the run position.
If OK, see the diagnosis for Instrument Cluster in
this group. If not OK, repair the open circuit to the
fuse in the junction block as required.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the rear window defogger relay from
the junction block.
INSTALLATION
(1) Install the rear window defogger relay by align-
ing the relay terminals with the cavities in the junc-
tion block and pushing the relay firmly into place.
(2) Connect the battery negative cable.
(3) Test the relay operation.
Fig. 4 DEFOGGER RELAY- TERMINAL LEGEND
KJWINDOW DEFOGGER 8G - 7
REAR WINDOW DEFOGGER RELAY (Continued)

HEATED SEAT SYSTEM
TABLE OF CONTENTS
page page
HEATED SEAT SYSTEM
DESCRIPTION.........................10
OPERATION...........................10
DIAGNOSIS AND TESTING - HEATED SEAT
SYSTEM............................11
DRIVER SEAT HEATER SWITCH
DESCRIPTION.........................11
OPERATION...........................12
DIAGNOSIS AND TESTING - HEATED SEAT
SWITCH............................12
REMOVAL.............................13
INSTALLATION.........................13
HEATED SEAT ELEMENT
DESCRIPTION.........................13OPERATION...........................13
DIAGNOSIS AND TESTING - HEATED SEAT
ELEMENT...........................13
HEATED SEAT SENSOR
DIAGNOSIS AND TESTING - HEATED SEAT
SENSOR............................14
PASSENGER SEAT HEATER SWITCH
DESCRIPTION.........................14
OPERATION...........................14
DIAGNOSIS AND TESTING - HEATED SEAT
SWITCH............................14
REMOVAL.............................15
INSTALLATION.........................15
HEATED SEAT SYSTEM
DESCRIPTION
Individually controlled electrically heated front
seats are available on models that are also equipped
with the optional leather trim package. Vehicles with
this option can be visually identified by the two sep-
arate heated seat switches mounted on the outboard
seat cushion side shields. The heated seat system
allows the front seat driver and passenger to select
from two different levels of supplemental electrical
seat heating, or no seat heating to suit their individ-
ual comfort requirements. The heated seat system for
this vehicle includes the following major components:
²Heated Seat Switches- Two heated seat
switches are used per vehicle, including two Light-
Emitting Diode (LED) indicator lamps and an incan-
descent back lighting bulb for each switch. One
switch for the driver and one for the passenger front
seats. The switches are mounted on the outboard
seat cushion side shields.
²Heated Seat Module- also referred to as the
Seat Heat Interface Module (SHIM), this module con-
tains the solid state electronic control and diagnostic
logic circuitry for the heated seat system. One heated
seat module is used per vehicle and is mounted
under the left front seat cushion. Refer to the Elec-
tronic Control Modules section of the service manual
for heated seat module information.
²Heated Seat Elements- Four heated seat ele-
ments are used per vehicle, one for each front seat
back and one for each front seat cushion. The ele-
ments are integral to the individual front seat andseat back cushions and cannot be removed from the
cushions, once installed at the factory.
²Heated Seat Sensors- Two heated seat sen-
sors are used per vehicle, one for each front seat. The
sensors are integral to the individual front seat heat-
ing elements.
Following are general descriptions of the major
components in the heated seat system. See the own-
er's manual in the vehicle glove box for more infor-
mation on the features, use and operation of the
heated seat system. Refer toWiring Diagramsfor
the location of complete heated seat system wiring
diagrams.
OPERATION
The heated seat module receives fused battery cur-
rent through fuse #29 in the Junction Block (JB)
when the ignition switch is in the ªONº position. The
heated seat switches receive battery current through
fuse #25 in the Junction Block also, when the igni-
tion switch is in the ªONº position. The heated seat
module shares a common ground circuit with each of
the heated seat elements. The heated seat elements
will only operate when the surface temperature of
the seat cushion is below the designed temperature
set points of the system.
The heated seat system will also be turned off
automatically whenever the ignition switch is turned
to any position except On. If the ignition switch is
turned to the Off position while a heated seat is
turned ON, the heated seat will remain Off after the
ignition switch is turned back ªONº until a heated
seat switch is depressed again.
8G - 10 HEATED SEAT SYSTEMKJ